[1.12.2] Render player's view as zoomed in image on screen

[Toma™]

Hello everyone, I'm trying to render player's view (basically everything on screen) into screen overlay (using RenderGameOverlayEvent). But I cannot get my head around it. I have tried using FrameBuffer texture, but it didn't work out really well. As you can see here.

Does anyone have any ideas how I would be able to achieve that?

Current code, don't think it's going to actually help
 

@SubscribeEvent
public static void renderOverlay(RenderGameOverlayEvent.Pre event) {
    if (event.getType() == RenderGameOverlayEvent.ElementType.ALL) {
        Minecraft mc = Minecraft.getMinecraft();
        Tessellator tessellator = Tessellator.getInstance();
        GlStateManager.bindTexture(mc.getFramebuffer().framebufferTexture);
        BufferBuilder builder = tessellator.getBuffer();
        builder.begin(7, DefaultVertexFormats.POSITION_TEX);
        builder.pos(x, y + h, 0).tex(0, 0).endVertex();
        builder.pos(x + w, y + h, 0).tex(1, 0).endVertex();
        builder.pos(x + w, y, 0).tex(1, 1).endVertex();
        builder.pos(x, y, 0).tex(0, 1).endVertex();
        tessellator.draw();
    }
}

 

edit: I know I have no zoom in code here, for now I'm mostly interested in getting it to work normally

Edited December 16, 2019 by Toma™

[Toma™]

Looks like framebuffer texture is not the way to go. I have found method in EntityRenderer called renderWorld. Looks like that could be what I'm looking for, but from quick observation I can see it sets the OpenGL viewport to minecraft display width and height, so I need to find a way, how to compress it into smaller rectangle. Anyone knows?